I care about the environment. In particular, I care about the existence and flourishing of animals. This is not a rare concern. Very many people are saddened by, for example, the fate of the Bengal tiger.

However, people killing tigers is not why tigers are endangered. We kill several orders of magnitudes more chickens per year, and yet gallus gallus domesticus is far from endangered. Tigers are endangered because they are not very useful to people, so secure property rights have never been created in them. However, if this were to change, then tigers would quickly flourish. For example, I could run a wilderness reserve, breed the tigers, and sell the right to hunt them. This model has allowed the rhino population in Namibia to recover, despite the objections of some doctrinaire environmentalists (see e.g. here).

In other words, tigers dwindle precisely because we relate to them as magnificent creatures that exist for their own sake. But chickens flourish because we relate to them as things we can make use of. Vegetarians are doing the devil's work by encouraging us to care about the chicken for its own sake. That way lies the end of the chicken. Resources are limited. Animals that aren't useful to people will be pushed to the margins and perhaps even extinction.

I for one dream of a glorious future where I can eat a snow-leopard burger with cutlery made from narwhal-horn, knowing that doing so is contributing to the continuation of these species.

I feel like you don't understand vegetarians very well. Lets say that I am wealthy slave owner in the middle 19th century. I could free my slaves but I think it would be more altruistic to instead use my money to set up schools for poor(white) kids. Does that mean I'm off the hook for keeping my slaves?